Integrated center and process for recycling both polyolefin and polyester

Abstract

An integrated, automated process for separating and recycling a broad mix of plastic waste material including, without limitation, polyester and polyolefin streams. The process begins by collecting the material. The material is then pre-processed to remove contamination. Next, the material is coarsely shredded, resulting in ground material. The ground material is friction washed to remove further contaminants from the ground material and form cleaned ground material. The cleaned ground material is sink floated to further wash the clean ground material and separate it into polyolefin flakes and polyester remainder. The polyester remainder is dried, yielding polyester flakes. Finally, the polyester flakes are collected. The process eliminates the tradeoffs between recovery and purity that perplex recycling facilities and permits simultaneous handling of polyesters and polyolefins. Also provided are a related center (and an infrastructure including the center) and at least one computer-readable non-transitory storage medium embodying software for performing the process.

What is claimed: 
     
         1 . An automated process for separating and recycling a broad mix of plastic waste material including, but not limited to, polyolefin and polyester streams, the process comprising:
 collecting the broad mix of plastic waste material;   pre-processing the broad mix of plastic waste material to remove contamination from the broad mix of waste material;   coarsely shredding or grinding the broad mix of plastic waste material, resulting in ground material;   friction washing the ground material to remove dirt, sand, grease, and other contaminants from the ground material and to form cleaned ground material;   sink floating the cleaned ground material to further wash and separate the clean ground material into recycled polyolefin and polyester remainder;   drying the polyester remainder, resulting in recycled polyester; and   collecting the recycled polyester.   
     
     
         2 . The automated process according to  claim 1  wherein the broad mix of plastic waste material that is collected includes one or more of polyethylene, polyethylene terephthalate, linear low density polyethylene, low density polyethylene, polypropylene, high density polyethylene, and polystyrene. 
     
     
         3 . The automated process according to  claim 1  wherein the step of pre-processing the broad mix of plastic waste material results in a premium bale. 
     
     
         4 . The automated process according to  claim 1  further comprising, after collecting the broad mix of plastic waste material, transporting the collected broad mix of plastic waste material to an integrated plastic recycling center where pre-processing occurs. 
     
     
         5 . The automated process according to  claim 1  wherein the step of pre-processing includes optical sorting the broad mix of plastic waste material. 
     
     
         6 . The automated process according to  claim 1  wherein the step of drying the polyester remainder is done at temperature levels of about 160-180° C. to a moisture content below about 0.005%. 
     
     
         7 . The automated process according to  claim 1  wherein the recycled polyolefin comprises flakes of polyolefin. 
     
     
         8 . The automated process according to  claim 1  wherein the recycled polyester comprises flakes of polyester. 
     
     
         9 . The automated process according to  claim 1  wherein the contamination removed from the broad mix of plastic waste material during pre-processing does not include plastics. 
     
     
         10 . The automated process according to  claim 1  wherein the contamination removed from the broad mix of plastic waste material during pre-processing includes non-recyclable plastic, and the process further comprises:
 sending the non-recyclable plastic to a landfill resulting in waste collection credits under a certified standard; and 
 sending the recycled polyolefin and the recycled polyester to one or more recyclers resulting in both waste collection credits and waste recycling credits under a certified standard. 
 
     
     
         11 . The automated process according to  claim 1  further comprising pelletizing the recycled polyester into pellets and subjecting the pellets to solid state polycondensation. 
     
     
         12 . An integrated plastic recycling center for separating and recycling a broad mix of plastic waste material including, but not limited to, polyolefin and polyester streams, the center comprising:
 a mechanism for collecting the broad mix of plastic waste material;   an optical sorter for pre-processing the broad mix of plastic waste material to remove contamination from the broad mix of plastic waste material;   a shredder for coarsely shredding or grinding the broad mix of plastic waste material, resulting in ground material;   a friction washing machine for removing dirt, sand, grease, and other contaminants from the ground material;   a sink float separation tank for further washing and separating the ground material, resulting in recycled polyolefin and polyester remainder; and   a dryer unit for drying the polyester remainder, resulting in recycled polyester.   
     
     
         13 . The integrated plastic recycling center according to  claim 12  wherein the sink float separation tank uses water as a medium to separate the ground material based on densities. 
     
     
         14 . The integrated plastic recycling center according to  claim 12  wherein the broad mix of plastic waste material that is collected by the mechanism includes one or more of polyethylene, polyethylene terephthalate, linear low density polyethylene, low density polyethylene, polypropylene, high density polyethylene, and polystyrene. 
     
     
         15 . The integrated plastic recycling center according to  claim 12  wherein the recycled polyolefin comprises flakes of polyolefin, the recycled polyester comprises flakes of polyester, or both. 
     
     
         16 . The integrated plastic recycling center according to  claim 12  wherein the optical sorter fractionates polyolefins into discreet colors and segregates food-grade packaging from non-food-grade packaging. 
     
     
         17 . A hub and spoke infrastructure for separating and recycling a broad mix of plastic waste material including, but not limited to, polyolefin and polyester streams, the infrastructure comprising:
 a plurality of materials recovery facilities collecting a first portion of the broad mix of plastic waste material;   a number of recycling facility/transfer stations both collecting a second portion of the broad mix of plastic waste material and receiving from at least one materials recovery facility the mixed plastic waste material collected by the at least one materials recovery facility; and   multiple integrated plastic recycling centers according to  claim 12 , each center collecting the broad mix of plastic waste material from one or more of the plurality of materials recovery facilities, from one or more of the recycling facility/transfer stations, or from both one or more of the plurality of materials recovery facilities and one or more of the recycling facility/transfer stations,   wherein each of the multiple centers is located geographically in relative proximity to the one or more materials recovery facilities, the one or more recycling facility/transfer stations, or to both the one or more materials recovery facilities and the one or more recycling facility/transfer stations from which the center collects the broad mix of plastic waste material.   
     
     
         18 . One or more computer-readable non-transitory storage media embodying software that is operable when executed to:
 collect a broad mix of plastic waste material including, but not limited to, polyolefin and polyester streams;   pre-process the broad mix of plastic waste material to remove contamination from the broad mix of plastic waste material;   coarsely shred or grind the broad mix of plastic waste material, resulting in ground material;   friction wash the ground material to remove dirt, sand, grease, and other contaminants from the ground material;   sink float the ground material to further wash and separate the ground material, resulting in recycled polyolefin and polyester remainder;   dry the polyester remainder, resulting in recycled polyester; and   collect the recycled polyester.   
     
     
         19 . An integrated process that constitutes recycling facilities and secondary processing centers with enhanced sorting, separating, and processing capabilities, the process comprising:
 delivering a stream or streams of recyclable waste material to recycling facilities wherein large volume materials including cardboard, glass, aluminum, and steel are sorted, baled, and sold to converters;   sending remaining material to secondary processing centers for further refinement, wherein the recycling facility enables market area collection and the secondary processing center is a larger regional hub;   aggregating material on a regional basis; and   sending a concentrated stream of difficult-to-process material through a purpose-built separation process step which would not be practical or economical on a de-centralized basis.   
     
     
         20 . The integrated process according to  claim 19 , further comprising separating the difficult-to-process material that includes rigid plastics into bales of primarily polyester in a first line and primarily polyolefin in a second line.